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Footnote 1 currently says
The main evidence is based on the resonance width of the Z0 boson, which constrains the 4th generation neutrino to have a mass greater than ~45 GeV/c². This would be highly contrasting with the other three generations' neutrinos, whose masses cannot exceed 2 MeV/c².
but as far as I can tell in the Standard Model there's no obvious reason why there should be as many generation of quarks as of leptons (though GUTs do predict that). Am I missing something? If not, I propose to remove that footnote as misleading. — A. di M. 18:29, 23 October 2018 (UTC)
How reliable is the Quark hypothesis?
First I would remaind you on the failure of the LHC-experiment at CERN. It was made to prove "Quarks" definitively.
Second: As we know were this particles predicted by theory. They have therefore merely theoretical need. It is questionable to declare the reality (in this case the world of particles and nuclei) by theoretical considerations. We have to be close to the experimental facts and observations.
Third it is possible to describe the world of particles and nuclei using the most elementary particles electron and positron. The world of particles is probably substantial differnt from the accepted theoretical description.
Some links:
http://www.erkennbare-welt.de/Teilchen&Kerne
hg.hil 2003:CE:ABC5:3FDB:888A:C133:AA37:8E4D ( talk) 09:21, 11 March 2019 (UTC)
https://youtube.com/watch?v=po-SQ33Kn6U -- Espoo ( talk) 00:13, 30 May 2019 (UTC)
This source clearly states that they're doing experiment with free quark, which exists in a state called quark-gluon plasma. Free quark means that it's no longer in confinement. Free quark = isolated quark. In color confinement, it clearly states that quark "cannot be isolated, and therefore cannot be directly observed in normal conditions below the Hagedorn temperature". It means that ABOVE the Hagedorn temperature, quark can be isolated and observed directly. Stop reverting my edits. You guys are probably amatuer in physics at best. Do you even know what I do for a living? I came across this article and saw a glaring error, so I decided to fix it. 2402:800:436F:5C80:C9D4:EFF:4DC3:6B91 ( talk) 02:39, 10 June 2020 (UTC)
Leave the lede alone. The final section addresses QGP without misleading flourishes. I first read Hagedorn’s paper in 1975; publishing in professional HEP literature since. You need to read up. This is not a forum. Cuzkatzimhut ( talk) 10:52, 10 June 2020 (UTC)
Sigh... Isolated quarks means asymptotic states, and not "asymptotically free quarks", as you might well be misconstruing them. You must be confused about the meaning of asymptotic freedom. Please go to the Quark–gluon plasma page for clarification. This is not a forum. Cuzkatzimhut ( talk) 12:33, 10 June 2020 (UTC)
"I mean free quarks" may be at the root of your misconception. An asymptotic state is completely isolated from any other quarks or excitations, here, colored ones. QGP is a medium replete with color degrees of freedom. While you might split hairs in the suitable section or article, messing with the lede in an important article to service tendentious misunderstandings is simply not OK. Cuzkatzimhut ( talk) 13:00, 10 June 2020 (UTC)
The footnote nb1 adducing QGP is still there! Cuzkatzimhut ( talk) 11:19, 11 June 2020 (UTC)
You are (again) misreading the sentences "Quarks carry color charge and cannot be observed directly as they hadronize to colorless particles before decaying. One exception is the top quark, as it decays before hadronization due to its short lifetime. " The exception is not to the directness, but to the hadronization, obviously. Most observations in HEP are indirect, but this one takes the prize. Cuzkatzimhut ( talk) 13:09, 11 June 2020 (UTC)
Sigh... The exception is in that the top decays before it hadronizes, so it cannot fail to be detected directly because of hadronization! That is, it has disappeared at a distance scale shorter than the size of the hadron in which it would be included, and certainly that of its decay products, b, etc. It has spent its entire life in the hadronic fireball in which it was created, of size smaller than a fermi, and certainly it has not "beaten confinement" in this blob! Cuzkatzimhut ( talk) 13:52, 11 June 2020 (UTC)
No, your are, in fact, arguing for the same thing! You observe the t indirectly, in the same way you are observing the s quark in a K decaying to pions, or the c quark in Ds. The authors never intended anyone to understand the decay of the t is not conventional, and indirect. You are investing "directly" with an eccentric meaning never intended. c ( talk) 15:46, 11 June 2020 (UTC)
To the extent that it needs repeating, Gell-Mann was diffident about quarks for 10 years, because of the (ultimately 30-year long) failure of isolated fractionally-charged particles' searches to bear fruit. This is the first feature a physics student or a layman should see about quarks, happening nowhere else in physics. Hitting them right away with qualifications, hair-splittings, and notional prestidigitations detracts from the central key point. There is plenty of room for finessing Hagedorn temps and their more usable analogs (!) later in the article, and in the penumbral technical articles linked. The key point is to not puzzle and confuse the eager novice with "ifs" and "but"s. Cuzkatzimhut ( talk) 19:01, 11 June 2020 (UTC)
Above the Hagedorn temperature, quarks break out of hadronic bound states and propagate as quasi-free excitations in an extended colored medium, not in the vacuum: they may not be said to be isolated. One infers their properties, not too differently than inferring the scattered quark properties from the features of a hadronic QCD jet. The statement of the color confinement article is muddy and misleading, in my view, but I have no experience with that page--it certainly didn't come out of Barger and Phillips cited! I believe it should be improved, but the novice hardly stumbles there. Cuzkatzimhut ( talk) 20:10, 11 June 2020 (UTC)
A free quark in Gell-Mann's, Zweig's, and Feynman's usage (no sources: I worked for them), and everybody else's (indeed), is an isolated quark coming from outer space, or hovering in space, or hitting a detector which thereby registers fractional charge, so, not hadronized; these were searched for for decades, unsuccessfully. They don't exist for a reason. QGP is normally a blob of no more than a few fermis wide, produced by the collision of hadrons or nuclei, and so, could be thought of as an extreme bag of colored entities. The fact that quarks propagate "freely" in it is hardly different, conceptually, than partons in a hadron struck at extreme s, so a huge contrast. That's just why the "free" terminology is deprecated in favor of "isolated". I'd be flattered to consider any of this as original research or interpretations! Cuzkatzimhut ( talk) 21:06, 11 June 2020 (UTC)
What happens with quark structure e.g. of proton + neutron when they bind into deuteron?
We know it has large electric quadrupole moment ( /info/en/?search=Deuterium#Magnetic_and_electric_multipoles ), what seems tough to get if thinking about it as just 'pn' (?)
It is explained by adding l=2 angular momentum, but it suggests some dynamics - what exactly?
Couldn't this quadrupole be obtained by just shifting some quarks instead? (I got such suggestion from soliton particle models) Jarek Duda ( talk) 07:07, 19 June 2020 (UTC)
It seems odd to attribute the discovery of quarks to SLAC without any mention of the Nobel Prize awarded for that work to Friedman, Kendall, and Taylor. Surely it merits a sentence. 174.62.81.41 ( talk) 03:05, 10 March 2023 (UTC)
This is the
talk page for discussing improvements to the
Quark article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
Archives:
1,
2,
3Auto-archiving period: 60 days
![]() |
![]() | Quark is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so. | |||||||||||||||||||||||||||||||||||||||
![]() | This article appeared on Wikipedia's Main Page as Today's featured article on September 15, 2009. | |||||||||||||||||||||||||||||||||||||||
|
![]() | This ![]() It is of interest to the following WikiProjects: | ||||||||||
|
This article was reviewed by
Nature (journal) on December 14, 2005. Comments: No significant errors or major omissions were found. For more information about external reviews of Wikipedia articles and about this review in particular, see this page. |
This page has archives. Sections older than 60 days may be automatically archived by Lowercase sigmabot III. |
Footnote 1 currently says
The main evidence is based on the resonance width of the Z0 boson, which constrains the 4th generation neutrino to have a mass greater than ~45 GeV/c². This would be highly contrasting with the other three generations' neutrinos, whose masses cannot exceed 2 MeV/c².
but as far as I can tell in the Standard Model there's no obvious reason why there should be as many generation of quarks as of leptons (though GUTs do predict that). Am I missing something? If not, I propose to remove that footnote as misleading. — A. di M. 18:29, 23 October 2018 (UTC)
How reliable is the Quark hypothesis?
First I would remaind you on the failure of the LHC-experiment at CERN. It was made to prove "Quarks" definitively.
Second: As we know were this particles predicted by theory. They have therefore merely theoretical need. It is questionable to declare the reality (in this case the world of particles and nuclei) by theoretical considerations. We have to be close to the experimental facts and observations.
Third it is possible to describe the world of particles and nuclei using the most elementary particles electron and positron. The world of particles is probably substantial differnt from the accepted theoretical description.
Some links:
http://www.erkennbare-welt.de/Teilchen&Kerne
hg.hil 2003:CE:ABC5:3FDB:888A:C133:AA37:8E4D ( talk) 09:21, 11 March 2019 (UTC)
https://youtube.com/watch?v=po-SQ33Kn6U -- Espoo ( talk) 00:13, 30 May 2019 (UTC)
This source clearly states that they're doing experiment with free quark, which exists in a state called quark-gluon plasma. Free quark means that it's no longer in confinement. Free quark = isolated quark. In color confinement, it clearly states that quark "cannot be isolated, and therefore cannot be directly observed in normal conditions below the Hagedorn temperature". It means that ABOVE the Hagedorn temperature, quark can be isolated and observed directly. Stop reverting my edits. You guys are probably amatuer in physics at best. Do you even know what I do for a living? I came across this article and saw a glaring error, so I decided to fix it. 2402:800:436F:5C80:C9D4:EFF:4DC3:6B91 ( talk) 02:39, 10 June 2020 (UTC)
Leave the lede alone. The final section addresses QGP without misleading flourishes. I first read Hagedorn’s paper in 1975; publishing in professional HEP literature since. You need to read up. This is not a forum. Cuzkatzimhut ( talk) 10:52, 10 June 2020 (UTC)
Sigh... Isolated quarks means asymptotic states, and not "asymptotically free quarks", as you might well be misconstruing them. You must be confused about the meaning of asymptotic freedom. Please go to the Quark–gluon plasma page for clarification. This is not a forum. Cuzkatzimhut ( talk) 12:33, 10 June 2020 (UTC)
"I mean free quarks" may be at the root of your misconception. An asymptotic state is completely isolated from any other quarks or excitations, here, colored ones. QGP is a medium replete with color degrees of freedom. While you might split hairs in the suitable section or article, messing with the lede in an important article to service tendentious misunderstandings is simply not OK. Cuzkatzimhut ( talk) 13:00, 10 June 2020 (UTC)
The footnote nb1 adducing QGP is still there! Cuzkatzimhut ( talk) 11:19, 11 June 2020 (UTC)
You are (again) misreading the sentences "Quarks carry color charge and cannot be observed directly as they hadronize to colorless particles before decaying. One exception is the top quark, as it decays before hadronization due to its short lifetime. " The exception is not to the directness, but to the hadronization, obviously. Most observations in HEP are indirect, but this one takes the prize. Cuzkatzimhut ( talk) 13:09, 11 June 2020 (UTC)
Sigh... The exception is in that the top decays before it hadronizes, so it cannot fail to be detected directly because of hadronization! That is, it has disappeared at a distance scale shorter than the size of the hadron in which it would be included, and certainly that of its decay products, b, etc. It has spent its entire life in the hadronic fireball in which it was created, of size smaller than a fermi, and certainly it has not "beaten confinement" in this blob! Cuzkatzimhut ( talk) 13:52, 11 June 2020 (UTC)
No, your are, in fact, arguing for the same thing! You observe the t indirectly, in the same way you are observing the s quark in a K decaying to pions, or the c quark in Ds. The authors never intended anyone to understand the decay of the t is not conventional, and indirect. You are investing "directly" with an eccentric meaning never intended. c ( talk) 15:46, 11 June 2020 (UTC)
To the extent that it needs repeating, Gell-Mann was diffident about quarks for 10 years, because of the (ultimately 30-year long) failure of isolated fractionally-charged particles' searches to bear fruit. This is the first feature a physics student or a layman should see about quarks, happening nowhere else in physics. Hitting them right away with qualifications, hair-splittings, and notional prestidigitations detracts from the central key point. There is plenty of room for finessing Hagedorn temps and their more usable analogs (!) later in the article, and in the penumbral technical articles linked. The key point is to not puzzle and confuse the eager novice with "ifs" and "but"s. Cuzkatzimhut ( talk) 19:01, 11 June 2020 (UTC)
Above the Hagedorn temperature, quarks break out of hadronic bound states and propagate as quasi-free excitations in an extended colored medium, not in the vacuum: they may not be said to be isolated. One infers their properties, not too differently than inferring the scattered quark properties from the features of a hadronic QCD jet. The statement of the color confinement article is muddy and misleading, in my view, but I have no experience with that page--it certainly didn't come out of Barger and Phillips cited! I believe it should be improved, but the novice hardly stumbles there. Cuzkatzimhut ( talk) 20:10, 11 June 2020 (UTC)
A free quark in Gell-Mann's, Zweig's, and Feynman's usage (no sources: I worked for them), and everybody else's (indeed), is an isolated quark coming from outer space, or hovering in space, or hitting a detector which thereby registers fractional charge, so, not hadronized; these were searched for for decades, unsuccessfully. They don't exist for a reason. QGP is normally a blob of no more than a few fermis wide, produced by the collision of hadrons or nuclei, and so, could be thought of as an extreme bag of colored entities. The fact that quarks propagate "freely" in it is hardly different, conceptually, than partons in a hadron struck at extreme s, so a huge contrast. That's just why the "free" terminology is deprecated in favor of "isolated". I'd be flattered to consider any of this as original research or interpretations! Cuzkatzimhut ( talk) 21:06, 11 June 2020 (UTC)
What happens with quark structure e.g. of proton + neutron when they bind into deuteron?
We know it has large electric quadrupole moment ( /info/en/?search=Deuterium#Magnetic_and_electric_multipoles ), what seems tough to get if thinking about it as just 'pn' (?)
It is explained by adding l=2 angular momentum, but it suggests some dynamics - what exactly?
Couldn't this quadrupole be obtained by just shifting some quarks instead? (I got such suggestion from soliton particle models) Jarek Duda ( talk) 07:07, 19 June 2020 (UTC)
It seems odd to attribute the discovery of quarks to SLAC without any mention of the Nobel Prize awarded for that work to Friedman, Kendall, and Taylor. Surely it merits a sentence. 174.62.81.41 ( talk) 03:05, 10 March 2023 (UTC)